| BackgroundPlain film is inaccurate and inadequate in the diagnosis of non-neoplastic and neoplastic conditions of PNS. Imaging of the PNS has progressed from the realm of conventional radiographs almost exclusively into the realms of computed tomography(CT) and magnetic resonance imaging(MRI). Technological advances in these two imaging modalities have provided more precise differential diagnosis and greater detail about the anatomic extent of the diseases of PNS. These provide sufficient information for diagnosis and surgical planning in the PNS diseases. CT has replaced conventional radiographs as imaging modality of choice for assessment of PNS diseases. CT plays an important diagnostic role in patients with sinonasal disease and determines the treatment. Excellent details are available regarding the anatomy, anatomic variants and pathology of PNS. CT determines the distribution and extent of disease and detect those anatomic variations(like septal deviation, spur formation, concha bullosa, paradoxical curve of middle turbinate etc.) that may place the patients at increased risk for intra operative and post operative FESS complications and there by reduces the morbidity and mortality of patients. It has a role in assessing relationship of the sinuses with the surrounding important structures. At present, CT scanning is the most used imaging technique for assessing chronic sinusitis and defining the anatomical abnormality.For the surgical treatment of inflammatory sinonasal disease, FESS has largely replaced more traditional sinus surgery techniques. The rationale for FESS is that these techniques allow restoration of the flow of sinus secretions through their native drainage portals, allowing the inflamed sinus to return to a normal state.CT Plays an important role in the pre-operative evaluation of patients considered for FESS called SSCT(Screening sinus CT). CT provides a “ROAD MAP” to guide the otorhinolaryngologist during surgery and serves to direct the surgical approach. There controversy for with regards to the advice of CT for the management of sinusitis and hence, this study was undertaken to correlate exists a between the CT findings and the endoscopic findings in FESS, the anatomical abnormalities and the mucosal changes in patients.Computed Tomography of the paranasal sinuses has improved the visualization of paranasal sinus anatomy and has allowed greater accuracy in evaluating paranasal sinus disease. Accurate delineation of the disease, its extent & complications, anatomical variations and vital relations of the paranasal sinuses by CT scan provides a reliable pre-operative road map. Multidetector CT(MDCT) enables us to obtain thin section scans and subsequent high quality multiplanar reformations.Objective To diagnose the disease of PNS and its complications and to ennumerate the detailed anatomy, anatomic variations and pathology of PNS which help the otorhinolaryngologist during FESS, thereby reducing the risk of complications.(screening sinus CT). To know the exact location and extent of the disease of PNS that is very important in deciding the management and to compare the accuracy of CT findings and diagnosis with that of FESS.Methodology This is a retrospective study design. Total of 40 patients were included in the study. Patients were of different age groups ranging from 13 years to 65 years with PNS diseases, underwent pre operative CT PNS followed by functional endoscopic sinus surgery(FESS). The parameters which were used for the correlation were paradoxical middle turbinate, concha bullosa, ostiomeatal complex disease, polypoidal changes, mucosal thickening, frontoethmoidal disease, etc. The equipment used is GE Bright Speed Elite 16 slice, Storz endoscope & camera with high definition monitor. Patient has to be in supine position and the region is the roof of frontal sinuses to inferior wall of maxillary sinuses and the scanogram is lateral & AP. The plane of imaging is Axial- parallel to hard palate and coronal & sagittal reconstruction. The mode is spiral and scan orientation is caudo-cranial. Slice thickness is 2.5mm, contiguous with pitch ranging from 1-1.5mm. Descriptive and inferential statistical analysis has been carried out in the present study. Diagnostic statistics such as Sensitivity, Specificity, PPV and NPV has been computed.Results Total of 40 patients were included in the study. Patients were of different age groups ranging from 13 years to 65 years, mean age of 31.9 years. Majority of patients were in 21 to 30 years of age compromising 40% of study population, followed by 31 to 40 years age group compromising 20%. Males were predominant in the study group with around 57.5 %. The main symptom the patient presented with was headache which was severe to cause discomfort in daily activities in 57.5 % followed by nasal obstruction as seen in 47.5 %. Fever was seen less often in around 27.5% of patients. Few patients had more than one symptom. Maxillary sinuses are the most commonly involved sinuses. Sphenoid sinuses are less commonly involved sinuses. Patholgies affecting the sinuses were broadly divided into polypoidal mucosal thickening and the collection. Polypoidal mucosal thickening was the most common pathology affecting all the sinuses. Most commonly seen in maxillary sinuses on CT(Right – 62.5%, Left – 70%). Bilateral aplastic frontal sinuses was seen 1 patient.. CT showed 96.5% sensitivity and 96.4% specificity for frontal sinus disease. CT showed 86% sensitivity and 97.3 % specificity for anterior ethmoidal sinus disease. CT showed 80.9 % sensitivity and 86.4% specificity for sphenoid sinus disease. Infundibulum is the most commonly obstructed component of the osteomeatal unit in CT(Right – 55%, Left – 47.5%). Agger nasi cells were found in 45%(n- 18) on right and 35%(n-14) on left on CT, 45%(n- 18) on right and 37.5%(n-15) on left on FESS. The attachment of uncinate process was to the middle turbinate was most commonly seen. In few patients it was attached to lamina papyracea, superior turbinate, ethmoidal roof and ethmoidal bulla. Middle turbinate variants which were included in this study are Paradoxical middle turbinate, Lamellar concha and Concha bullosa.. Fovea was assessed only on CT. Fovea were symmetrical in 82.5% of the study population, of which Type II was commonest(52.5%). Fovea were asymmetrical in 17.5% of the study population. Sinonasal polyposis was the commonest pattern seen on CT in 17.5% of the study population, followed by Osteomeatal pattern and Infundibular pattern which had similar incidence(10%).Conclusion CT was superior in detecting OMC involvement, presence of concha bullosa, paradoxical turbinate and nasal septal deviation. Paradoxical turbinate was not easily detected on nasal endoscopy and was easily mistaken for concha bullosa by an inexperienced endoscopist. Concha bullosa was the commonest anatomical variation detected on endoscopy and has a higher degree of detection rate. This study also found that polyps, diseased mucosa and mucopus in the middle meatus have non specific features on coronal CT and endoscopy has an essential role in accurately diagnosing this pathology. An understanding of the disease process and its presentation in correlation to nasal endoscopic findings will assist radiologist in interpreting the CT findings. Functional interactive partnership between the radiologist and otolaryngologist is likely to yield a positive outcome that benefits both physicians and patients. |
PDF Full Text Request